Yes, many thanks to Tiamo!! [...]Any problem with the future 10.9.2? Upgrade is possible from 10.9.1?

Af far as I know, after updating to 10.9.2 you'll have to apply again the boot.efi patched files, because the previous ones will be overwritten, rendering the Mac Pro unbootable.(See preceding post by wojtek.)

There is 59 pages of reading material on the subject.Can anybody make a summary on all the different ways to be able to install Mountain Lion (64bit)So far I have seen many different ways on doing so. What is the best way, what is the advantages between one way from the other. Thanks.

The two most common ways to install Mountain Lion or Mavericks are:1.) Chameleon using Legacy Boot derived from Hackintosh. This is described at the beginning of this thread.2.) A boot.efi modified by tiamo with updated parameter plists that uses the OS X native boot mechanism bridging the gap between the 64 bit kernel and 32 bit EFI services to NVRAM etc. This is described here:http://forums.macrumors.com/showthread.php?t=1598176&page=2

I have switched to the newer mode using the boot.efi. It is simple and stable, the system boots and behaves as if it was never excluded from 64 bit mode. Note that the boot.efi is optimized for Mavericks, although it will support Mountain Lion (slower boot.) Read the thread all the way, there are two versions of the modified boot.efi - the first one is verbose, the second has the standard UI.

By far the easiest way to install this is to move the drive to a second system that support Mavericks, install the OS, and then switch the boot.efi in two locations and update the plists. Then you can move the drive to your Mac Pro and just boot.

But there are also various ways to directly bring it up on the Mac Pro, if you have no other system available.

That is the way I did it in the beginning and how I will do. To me its easier to pull the drive out and install the boot_efi and pop it back in. I thought about putting 10.7 on a partition. I real am enjoying this!

Yes, many thanks to Tiamo!! [...]Any problem with the future 10.9.2? Upgrade is possible from 10.9.1?

Af far as I know, after updating to 10.9.2 you'll have to apply again the boot.efi patched files, because the previous ones will be overwritten, rendering the Mac Pro unbootable.(See preceding post by wojtek.)

After updating to 10.9.2, I'm unable to remove the old boot.efi... because it is lock... is it possible to unlunck it and to trash it? Thanks!

1. Open the Terminal. 2. Type the following command, followed by a single space (do not press enter yet). sudo chflags nouchg 3. Drag the locked file from the Finder to the Terminal window to complete its full folder path. 4. Press Enter to run the command, supplying your password when prompted.When run, this command will undo the lock flag for the file, regardless of whether you own the file. While an enabled lock will prevent the file from being edited, ultimately it is designed to be a temporary hurdle that can be undone by any user who has access to the file.

1. Open the Terminal. 2. Type the following command, followed by a single space (do not press enter yet). sudo chflags nouchg 3. Drag the locked file from the Finder to the Terminal window to complete its full folder path. 4. Press Enter to run the command, supplying your password when prompted.When run, this command will undo the lock flag for the file, regardless of whether you own the file. While an enabled lock will prevent the file from being edited, ultimately it is designed to be a temporary hurdle that can be undone by any user who has access to the file.

I have a GT630 and updated one of the drives to 10.10 and installed Tiamo boot.EFI plus did chown and blessed the folder. I did get a chime but nada. Took the drive out to make sure ownership is correct. Tried again and could hear the drive working. Went back to iMac and low and behold it did boot up blind. I still have a SSD drive with 10.9.5 which the Gt630 works fine. I did check Nvidia site but no joy on drivers. Any thoughts??

Wow, very odd. I did the drill from 10.9.5 hard drive in terminal with the “Piker-Alpha” boot loader as you suggested. But some how, the original Apple boot_EFI was still in System/Library/CoresServices folder with the lock. I know I did the sudo chflags nouchg so I could delete it and put “Piker-Alpha” in. Still no joy. SO I pulled out the drive put in a USB dock and that’s when I saw the Apple boot_EFI with lock. So I redid it and redid the bless. I also did a get info on the files to see if they were correct, but before I removed it I re-did permission repair.Put the drive back in and this time I could hear the drive churning. It did boot up. Thank you,Lou Cioccio

helloI want to know how to set the partition to boot in 64 in place of 32.if you can send me a boot image created I could put my score this allow myself to work with my mac Yosemite 10.10.1 pro 1.1 I Thank You in advance and waiting for your new I joined you my email :"Wolf1734@hotmail.fr"kind regards